Source file src/pkg/cmd/go/internal/fmtcmd/fmt.go

     1	// Copyright 2011 The Go Authors. All rights reserved.
     2	// Use of this source code is governed by a BSD-style
     3	// license that can be found in the LICENSE file.
     4	
     5	// Package fmtcmd implements the ``go fmt'' command.
     6	package fmtcmd
     7	
     8	import (
     9		"fmt"
    10		"os"
    11		"path/filepath"
    12		"runtime"
    13		"strings"
    14		"sync"
    15	
    16		"cmd/go/internal/base"
    17		"cmd/go/internal/cfg"
    18		"cmd/go/internal/load"
    19		"cmd/go/internal/modload"
    20		"cmd/go/internal/str"
    21	)
    22	
    23	func init() {
    24		base.AddBuildFlagsNX(&CmdFmt.Flag)
    25	}
    26	
    27	var CmdFmt = &base.Command{
    28		Run:       runFmt,
    29		UsageLine: "go fmt [-n] [-x] [packages]",
    30		Short:     "gofmt (reformat) package sources",
    31		Long: `
    32	Fmt runs the command 'gofmt -l -w' on the packages named
    33	by the import paths. It prints the names of the files that are modified.
    34	
    35	For more about gofmt, see 'go doc cmd/gofmt'.
    36	For more about specifying packages, see 'go help packages'.
    37	
    38	The -n flag prints commands that would be executed.
    39	The -x flag prints commands as they are executed.
    40	
    41	To run gofmt with specific options, run gofmt itself.
    42	
    43	See also: go fix, go vet.
    44		`,
    45	}
    46	
    47	func runFmt(cmd *base.Command, args []string) {
    48		printed := false
    49		gofmt := gofmtPath()
    50		procs := runtime.GOMAXPROCS(0)
    51		var wg sync.WaitGroup
    52		wg.Add(procs)
    53		fileC := make(chan string, 2*procs)
    54		for i := 0; i < procs; i++ {
    55			go func() {
    56				defer wg.Done()
    57				for file := range fileC {
    58					base.Run(str.StringList(gofmt, "-l", "-w", file))
    59				}
    60			}()
    61		}
    62		for _, pkg := range load.PackagesAndErrors(args) {
    63			if modload.Enabled() && pkg.Module != nil && !pkg.Module.Main {
    64				if !printed {
    65					fmt.Fprintf(os.Stderr, "go: not formatting packages in dependency modules\n")
    66					printed = true
    67				}
    68				continue
    69			}
    70			if pkg.Error != nil {
    71				if strings.HasPrefix(pkg.Error.Err, "build constraints exclude all Go files") {
    72					// Skip this error, as we will format
    73					// all files regardless.
    74				} else {
    75					base.Errorf("can't load package: %s", pkg.Error)
    76					continue
    77				}
    78			}
    79			// Use pkg.gofiles instead of pkg.Dir so that
    80			// the command only applies to this package,
    81			// not to packages in subdirectories.
    82			files := base.RelPaths(pkg.InternalAllGoFiles())
    83			for _, file := range files {
    84				fileC <- file
    85			}
    86		}
    87		close(fileC)
    88		wg.Wait()
    89	}
    90	
    91	func gofmtPath() string {
    92		gofmt := "gofmt"
    93		if base.ToolIsWindows {
    94			gofmt += base.ToolWindowsExtension
    95		}
    96	
    97		gofmtPath := filepath.Join(cfg.GOBIN, gofmt)
    98		if _, err := os.Stat(gofmtPath); err == nil {
    99			return gofmtPath
   100		}
   101	
   102		gofmtPath = filepath.Join(cfg.GOROOT, "bin", gofmt)
   103		if _, err := os.Stat(gofmtPath); err == nil {
   104			return gofmtPath
   105		}
   106	
   107		// fallback to looking for gofmt in $PATH
   108		return "gofmt"
   109	}
   110	

View as plain text